The present invention relates to a container for organism sample and more particularly to a small-sized tubular container for organism sample having a cap (hereinafter referred to as "minispitz") for containing, inspecting and/or preserving an organism sample such as blood and urine, which is particularly suitable for refrigeration storage of blood serum for a long period of time.
Hitherto, there have been carried out biochemical inspections such as inspections of blood sugar to diagnose diabetes, when diagnosing disease of viscera such as liver, kidney, and pancreas. In such biochemical inspections, containers for organism sample are used to inspect organism sample, to centrifuge the organism sample prior to the inspection, and to preserve the organism sample till the inspection. Test tubes, Petri dishes, and the like are used as containers for organism sample. Among them, test tubes for collecting, preserving, centrifuging, and the like are widely used in various kinds of examinations or inspections.
Among the above-mentioned various kinds of test tubes, one suitable for the centrifugation treatment is called "spitz". A lower or bottom portion of a spitz is generally formed to have a spired contour. Decantation can be easily carried out when using a spitz because the inside diameter of the open upper end of the spitz (hereinafter referred to as "mouth") is equal to, or slightly larger than the inside diameter of a body portion of the spitz. That is to say, when a fluid sample is contained and centrifuged, a supernatant fluid of the centrifuged sample can be easily poured from the spitz into another container by leaning the spitz.
When using, for example, blood as a sample, a spitz is generally used to contain and centrifuge the blood, and thereafter to pour a supernatant fluid, i.e. blood serum, from the spitz to another container which might be a spitz. A spitz is also used to contain blood corpuscle or blood serum and to inspect or preserve them. In particular, a small-sized spitz having a cap called "minispitz" is widely used for the purpose of preservation.
A conventional minispitz has such a construction that a cap is merely inserted into the inside of a cylindrical body portion of the minispitz. When, for example, blood serum is preserved for a long period of time, the minispitz is sometimes preserved at a ultra-low temperature of minus 80.degree. C. in order to prevent the deterioration of blood serum during the preservation. In that case, there is caused a problem that the cap inserted into the body portion of the minispitz is opened. The reason why the cap is opened is probably that an inside pressure of the minispitz relatively becomes positive during the preservation at a ultra-low temprature of as low as minus 80.degree. C.
Further, when preserving a large number of minispitzes, a wrong sample was often taken due to the small size thereof.
The present invention was made to solve the above-mentioned drawbacks and a first object of the present invention is to provide a minispitz of which cap is not opened even when the minispitz is preserved at a ultra-low temperature. It is a second object of the present invention to further provide a minispitz suitable for a refrigeration storage at a ultra-low temperature, by which there is no danger of taking the wrong minispitz on inspection.